Aspects to be solved in gamma rays evaluation of hollow cylinders. Case of cast valve weld ends: solutions derived by computer

Quality control specialists are faced with several alternatives when requiring the radiographic examination of hollow cylindrical forms. This article considers gamma ray isotopic sources and analyses the different problems that must be overcome in order to make a correct choice of the exposure parameters for hollow cylinders. As an example, the examination of body weld ends of cast valves is described where both adverse geometrical and high radiographic quality requirements are often needed. Finally, experiments are described on systematization of methods for deriving parameters with computer help. (author)